We evaluated the ability of a ready-to-drink oolong tea (OOL) to modulate plasma antioxidant status in healthy subjects, compared to a placebo drink (PLA) without oolong extract but with ascorbic acid. In vitro, ascorbic acid was the only contributor to ferric reducing antioxidant power (FRAP) and total radical-trapping antioxidant parameter (TRAP) assay of PLA. Ascorbic acid contributed 16.5% and 9.7% of the antioxidant capacity of OOL In vivo, ingestion of 500 mL of OOL significantly increased plasma TRAP at 30 min and 1 h, compared to 500 mL of PLA, which was ineffective. Plasma FRAP significantly increased at 1, 2 and 4 h for OOL and at 2 h for PLA. Both PLA and OOL significantly increased urinary FRAP over 0-5 h. Urinary FRAP levels went back to baseline at 5 h for PLA tea and remained higher for OOL tea in the interval time 5-12 h (p < 0.01). OOL represents a dietary source of antioxidants able to modulate antioxidant status in humans. (C) 2011 Elsevier Ltd. All rights reserved.
Effect of acute consumption of oolong tea on antioxidant parameters in healthy individuals
Guadagni F;
2012-01-01
Abstract
We evaluated the ability of a ready-to-drink oolong tea (OOL) to modulate plasma antioxidant status in healthy subjects, compared to a placebo drink (PLA) without oolong extract but with ascorbic acid. In vitro, ascorbic acid was the only contributor to ferric reducing antioxidant power (FRAP) and total radical-trapping antioxidant parameter (TRAP) assay of PLA. Ascorbic acid contributed 16.5% and 9.7% of the antioxidant capacity of OOL In vivo, ingestion of 500 mL of OOL significantly increased plasma TRAP at 30 min and 1 h, compared to 500 mL of PLA, which was ineffective. Plasma FRAP significantly increased at 1, 2 and 4 h for OOL and at 2 h for PLA. Both PLA and OOL significantly increased urinary FRAP over 0-5 h. Urinary FRAP levels went back to baseline at 5 h for PLA tea and remained higher for OOL tea in the interval time 5-12 h (p < 0.01). OOL represents a dietary source of antioxidants able to modulate antioxidant status in humans. (C) 2011 Elsevier Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
